Sheet cleaning apparatus with cartridge roller assembly

ABSTRACT

A sheet cleaning apparatus having sets of cleaning rollers, wherein the rollers are integrated into a removable cartridge structure. Couplers are provided at roller shaft ends to connect to the roller drive. The cartridge is received in a slide carriage, permitting the cartridge to be readily removed from the apparatus by sliding the carriage out, and lifting the cartridge out from the slide carriage. With this arrangement, the down time for the sheet cleaning apparatus is minimized, since the sheet cleaning apparatus can be provided with two cartridges, and the cartridge needing maintenance can simply be quickly removed and replaced with a fresh cartridge. The production line can quickly be put back into operation, and the removed cartridge can be serviced off line for subsequent use.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to an improved apparatus for cleaning dustand other surface particulate contaminants from material in sheet form.

BACKGROUND OF THE INVENTION

This invention is an improvement to the sheet cleaning apparatusdescribed in U.S. Pat. No. 5,349,714, the entire contents of which areincorporated herein by reference. These apparatus are typically arrangedin a printed circuit board production line, with other, very expensivemachines. When the sheet cleaning apparatus needs servicing, typicallyto clean the sheet cleaning rollers (52, 54, 56, 58, shown e.g. in FIG.8), the apparatus must be disassembled to remove the rollers, or theoperator must clean the rollers in place. With either technique,considerable time is required for this maintenance procedure, idling notonly the sheet cleaning apparatus but the other, very expensive machineson the production line.

It would therefore be advantageous to provide a sheet cleaning apparatuswhich can be quickly serviced to minimize the machine down time.

SUMMARY OF THE INVENTION

To overcome the foregoing problems, a sheet cleaning apparatus isdescribed, having one or more sets of cleaning rollers, wherein therollers are integrated into a removable cartridge assembly. Couplers areprovided at roller shaft ends to connect to the roller drive. Thecartridge assembly is held in a slide carriage, permitting the cartridgeassembly to be readily removed from the apparatus by sliding thecarriage out, and lifting the cartridge out from the slide carriage.With this arrangement, the down time for the sheet cleaning apparatus isminimized, since the sheet cleaning apparatus can be provided with twocartridges, and the cartridge needing maintenance can simply be quicklyremoved and replaced with a fresh cartridge. The production line canquickly be put back into operation, and the removed cartridge can beserviced off line for subsequent use.

BRIEF DESCRIPTION OF THE DRAWING

These and other features and advantages of the present invention willbecome more apparent from the following detailed description of anexemplary embodiment thereof, as illustrated in the accompanyingdrawings, in which:

FIG. 1 is a front view of a sheet cleaning apparatus embodying theinvention.

FIG. 2 is a side cross-sectional view taken along line 2--2 of FIG. 1.

FIG. 3 is a side view illustrating the relative orientation of the sheetcleaning rollers and the roller cleaning adhesive rolls.

FIG. 4 is a simplified perspective view illustrating an exemplarymotor/gear drive arrangement for driving the roller couplers.

FIG. 5 illustrates the sheet cleaning apparatus with the rollercartridge exposed and removed from the cartridge slide arrangement forreplacement.

FIG. 6 is an exploded view of the drive end of the cartridge rollerassembly.

FIG. 7 is an isometric view of a roller lifting device employing in theapparatus of FIG. 1 to bias the position of the upper set of sheetcleaning rollers upwardly for separation from the lower set of sheetcleaning rollers when the apparatus is not in use.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1-7 illustrate an exemplary embodiment of a sheet cleaningapparatus 50 embodying the invention. The apparatus 50 includes twopairs of sheet-contacting cleaning rollers 52, 54 and 56, 58. Rollers 52and 54 are disposed in vertical alignment adjacent each other to definea nip 62. The surfaces of the cleaning rollers 52, 54, 56, 58 aredefined by a layer of resilient compressible material which has asurface tack or adhesion sufficient to transfer dust and other foreignparticulate contamination from a sheet coming into compressive contactwith the roller surface. It is also desirable that the roller surfacesbe smooth, in order to obtain complete contact with the surface of asheet pressed against the surface. Typically, the roller surfaces willhave a Shore A durometer value of up to 35.

In order to clean the surfaces of the sheet cleaning rollers 52-58,rolls 64, 66 of adhesive-coated tape are provided. These rolls 64, 66are disposed so as to be in contact with respective surfaces of rollers52-58 during sheet cleaning operations, as shown in FIG. 3. In a generalsense, the rolls 64, 66 are defined by rolls of tape having the adhesivecoating on the outward facing sides. The external surface of each of therolls 64, 66 has a surface tack which greatly exceeds the surface tackof the sheet cleaning rollers 52-58, in order to transfer the foreignparticles from the sheet cleaning rollers 52-58 to the surfaces of rolls64, 66.

To the extent just described, the apparatus 50 is similar to thatdescribed in U.S. Pat. No. 5,349,714.

The apparatus 50 includes a system for applying a variable preloadforce, urging roller 64 into engagement with surfaces of rollers 52 and56, and urging roller 66 into engagement with surfaces of rollers 54 and58. The system includes pneumatic cylinders 100 and 102 which supportthe lower tape roller 66, and pneumatic cylinders 104 and 106 whichapply pressure to the upper tape roller 64. Cylinder 100 includes a rod100A driven by a cylinder piston to an extended position. The rod isattached to a coupler 100B which has an opening into which an end ofshaft 67 carrying roll 66 is inserted. Cylinder 102 includes rod 102Adriven by a cylinder piston to an extended position. Rod 102A isattached to a coupler 102B which has an opening into which the opposedend of shaft 67 is inserted. The roll 66 is therefore supported by thesystem comprising cylinders 100 and 102 and couplers 100B and 102B. Thecylinders 100 and 102 are single acting, spring biased devices, whereinthe rods are spring biased to the fully retracted position, and the rodsare extended against the bias when pneumatic pressure is applied to thecylinders. Further the compression contact force of the roll 66 inrelation to the sheet cleaning rollers 54 and 58 is adjustable byadjusting the pneumatic pressure applied to the cylinders 100 and 102.

The system further includes pneumatic cylinders 104 and 106 which applypressure to the upper tape roller 64. Cylinder 104 includes a rod 104Adriven by a cylinder piston to an extended position. The rod is attachedto a coupler 104B which has an U-shaped opening into which a portion ofshaft 65 carrying roll 64 and adjacent a shaft end is received. Cylinder106 includes rod 106A driven by a cylinder piston to an extendedposition. Rod 106A is attached to a coupler 106B which has an openinginto which a portion of shaft 67 adjacent the opposite end of the shaftis received. The cylinders 104 and 106 are single acting, spring biaseddevices, wherein the rods are spring biased to the fully retractedposition, and the rods are extended against the bias when pneumaticpressure is applied to the cylinders. Further the compression contactforce of the roll 64 in relation to the sheet cleaning rollers 52 and 56is adjustable by adjusting the pneumatic pressure applied to thecylinders 104 and 106.

The shaft 65 is carried by spring-loaded bracket assemblies 72 and 74.Exemplary bracket assembly 72 is illustrated in FIG. 7, and includesouter bracket fixture 72A, sliding bracket 72B which fits within theouter fixture for sliding movement, and bias spring elements 72D and72E. The spring elements bias the relative position of the slidingbracket 72B to the upper position shown in FIG. 7, and upon applicationof force, the springs are compressible to permit the bracket 72B toslide down. Assembly 74 is identical to assembly 72. Together, theseassemblies bias the upper tape roll 64 to an elevated position out ofcontact with the cleaner rollers 52, 56 when the machine is idle, i.e.when the pneumatic pressure for the cylinders 104 and 106 is released.This prevents the tape roll surface from adhering to the cleaner rolleras a result of extended stationary contact. When the pneumatic pressureis removed from the cylinders 100, 102, the lower tape roll 66 drops byforce of gravity out of contact with the lower set of cleaner rollers54, 58, and is supported by a V-shaped cradle in brackets 76, 78. Nospring biasing is employed in connection with brackets 76, 78, sincesuch biasing would tend to keep the tape roll surface in contact withthe surfaces of the lower cleaner rollers after the pneumatic pressureis released.

In accordance with an aspect of the invention, the cleaner rollers arearranged in an easily removable cartridge assembly 120. The assembly 120is mounted on a slide assembly 130 which permits the cartridge assemblyto be moved from a working position, with the cleaner rollers inposition within the apparatus 50 for operation, and a maintenanceposition (shown in FIG. 5) with the cleaner rollers and the cartridgeassembly slid outside the housing 50A of the cleaner apparatus 50 forready replacement of the cartridge 120.

As shown in FIG. 5, the slide assembly 130 includes a carriage member132 which receives the cartridge assembly 120. Four mounting tabs 122 onthe carriage assembly have holes 122A formed therein. The cartridgeassembly 120 is dropped and locked into position on the carriage 132,with pins 134 extending upwardly from the carriage 132 and receivedthrough holes 122A registering the position of the cartridge 120 on thecarriage 132. The cartridge assembly is locked into position byspring-loaded locking tabs (not shown) formed with the pins 134, whichlocking tabs spring out after cartridge assembly has dropped onto thepins to lock the cartridge in position. This prevents the cartridge frombeing lifted from the carriage by the tackiness of the roll 64 aspressure is released from the pneumatic system. Other types of lockingarrangements can readily be employed. The carriage 132 is mountedbetween a first set of opposed slide rails 136A, 136B, which in turn aremounted on a second set of opposed slide rails 138A, 138B. The secondset of rails 138A, 138B are mounted on bearings (not shown) mounted tothe housing 50A to permit the second set of rails to slide outwardlyalso. The first set of rails is mounted on bearings to permittelescoping of the first and second sets of rails. The slide rails andbearings are parts of a commercially available slide assembly, such asthe three-section linear drawer slides marketed by Jonathan Company,Fullerton, Calif., which lock in both the closed and open positions.

The cartridge assembly 120 is shown in further detail in FIG. 6. Siderails 124A, 124B and end rails 126A, 126B form a carriage structurewhich carries the lower set of cleaner rollers 54, 58. The rollersrotate on respective shafts 54A, 58A which in turn are mounted onbearings fitted in openings formed in the end rails. For example,bearings 126AA and 126AB are mounted in end rail 126A. Only the driveend of the carriage assembly 120 is visible in FIG. 5. The lower set ofrollers are driven by a motor drive 150 (FIGS. 1 and 4) through a drivecoupler 160. The roller shafts 54A, 58A have flats 54AA, 58AA formedadjacent the shaft ends to form D-shaped shaft ends for mating withcorresponding D-shaped openings 162A, 164A formed in hexagonal malecoupler elements 162, 164 to prevent rotation of the coupler elements onthe shafts, while permitting axial sliding movement of the couplerelements on the shafts. Springs 166A, 166B are fitted on the shafts andextend between an end surface of rail 126A and the coupler elements 162and 164 to urge the coupler elements away from the end surface of rail126A. Snap rings 168A, 168B lock into position in grooves 54AB and 58ABto lock the coupler elements 162, 164 onto the shafts, after assembly ofthe springs 166A, 166B and the coupler elements onto the shafts. Thecoupler elements 162, 164 are formed with conical end surfaces 162B,164B which act as lead-in surfaces to align the male hexagonal couplerelements with corresponding female driven hexagonal coupler elements170, 172 shown in the isolation perspective view of FIG. 4. The drivencoupler elements are mounted on shafts 174, 176. Sprocket gears 178, 180are mounted on the respective shafts 174, 176, and have an endless chain182 mounted thereon. The shaft 176 also has a beveled gear 184 mountedthereon, which meshes with beveled gear 186 mounted on the motor shaft188. The cleaner rollers 54, 58 are driven in the same direction by themotor drive 150.

The upper cleaner rollers 52, 56 are not actively driven. Referringagain to FIG. 6, the upper rollers are mounted to the cartridge assembly120 by upper end rails 127A, 127B. The roller shafts 52A, 56A arereceived in corresponding bores (e.g. 127AA, 127AB) formed in the upperend rails. The upper end rails are slidably mounted on pins 128A, 128Bwhich are received in bores (e.g. bores 127AC, 127AD) formed in theupper end rails. Springs (e.g., springs 129A, 129B) can be fitted on thepins to provide a bias force tending to separate the upper end rails127A, 127B from the lower end rails 126A, 126B. This in turn biases theupper set of cleaner rollers 52, 56 away from the lower set of rollers54, 58. The upper set of pneumatic cylinders 104, 106 can exert a forceon the tape roll 64 to push the upper set of rollers toward the lowerset of rollers. The bias action of the springs, biasing the upper set ofrollers away from the lower rollers and therefor tending to increase thenip gap, provides the advantage of facilitating the cleaning of thickersheets for cleaning without adjusting the apparatus. For someapplications, it is preferable to omit the springs fitted on the pins.

The cleaning apparatus employs a pneumatic supply and control systemsimilar to that described in U.S. Pat. No. 5,349,714, and illustrated atFIG. 9. Similarly, the control circuit of FIG. 10 in U.S. Pat. No.5,349,714 can be employed to control the motor drive 150. The pneumaticsupply and control system and the motor drive control circuit thereforeneed not be described in further detail herein.

The cartridge assembly 120 can easily be replaced with a freshcartridge. This can be done by releasing the pressure on the pneumaticcylinders 100-106, so that the tape rolls move out of engagement withthe cleaner rollers 52-58. The latch of the slide assembly is thenreleased, and the carriage 132 is pulled from the operating position tothe maintenance position shown in FIG. 5. As the carriage is pulled outaway from its operating position, the drive coupler elements 162, 164become disengaged from the mating coupler elements 170, 172, therebydisconnecting the cartridge from the motor drive 150. The cartridge 120is then removed, without the use of tools in this exemplary embodiment,by lifting the assembly up and out of engagement with the pins 134. Oncethe cartridge assembly 120 is removed from the carriage 132, it canquickly be replaced by a fresh cartridge with clean sets of rollers52-58. Once a fresh cartridge is positioned in the carriage 132, theoperator slides the carriage into the operating position. As thecarriage slides into position, the coupler elements 162, 164 arereceived within the coupler elements 170, 172. There may be some initialrotational misalignment between the hexagonal mating elements. If so,the springs 166A, 166B compress as the elements 162, 164 are pushedtoward the end rail 126A. The conical surfaces 162B, 164B tend to alignthe mating elements by acting as a lead-in surface. Even if the matingelements do not engage as the cartridge is slid into the operatingposition, the first time the motor drive is actuated, as the outercoupler elements 170, 172 are turned by the motor drive, the matingelements will come into alignment, and the springs 166A, 166B will urgethe elements 162, 164 into an engaged aligned position relative to theouter mating elements 170, 172.

The sheet cleaning apparatus can be quickly serviced by replacement ofthe cartridge assembly 120, thus minimizing the machine down time. Theremoved cartridge assembly 120 can be serviced off line. The upper setof rollers 52, 56 can easily be removed from the cartridge assembly forcleaning, and to expose the lower set of rollers for cleaning.

It is understood that the above-described embodiments are merelyillustrative of the possible specific embodiments which may representprinciples of the present invention. Other arrangements may readily bedevised in accordance with these principles by those skilled in the artwithout departing from the scope and spirit of the invention.

What is claimed is:
 1. A sheet cleaning apparatus for cleaning foreignparticles from at least one surface of a sheet, comprising:a frame; aremovable sheet cleaning roller cartridge assembly including at leastone sheet cleaning roller rotatably secured thereto for rotation about asheet cleaning roller axis, said roller comprising a layer of resilientmaterial defining a peripheral roller surface with a high surface tackadapted to transfer foreign particles from said sheet to said peripheralroller surface upon contact and subsequent separation therebetween whileaffording clean separation between the sheet and said peripheralsurface; a roller cleaning member having a contact surface with agreater surface tack with respect to said foreign particles than saidsheet cleaning roller surface, said contact surface adapted to transfersaid foreign particles from said peripheral surface of said cleaningroller to said contact surface of said roller cleaning member duringsheet cleaning operations, said roller cleaning member having anexternal surface defining said contact surface and a cleaning elementaxis arranged substantially parallel to said roller axis; mountingapparatus for mounting said roller cartridge assembly in relation tosaid frame, said mounting apparatus permitting ready removal andreplacement of said roller cartridge assembly with another rollercartridge assembly to minimize down time of said sheet cleaningapparatus while permitting off-line servicing of said removed rollercartridge assembly.
 2. The apparatus of claim 1 wherein said mountingapparatus is adapted to permit movement of said roller cartridgeassembly between an operating position in an apparatus operating modewherein the sheet cleaning roller is in position for sheet cleaningoperation and a maintenance position during an apparatus maintenancemode wherein said cartridge assembly is accessible for servicing.
 3. Theapparatus of claim 2 wherein said mounting apparatus includes acartridge carriage and a slide apparatus to which said carriage ismounted, said slide apparatus adapted to permit sliding movement of saidcartridge carriage along a slide axis parallel to said roller axisbetween said operating position and said maintenance position.
 4. Theapparatus of claim 3 wherein said carriage includes cartridge positionregistration elements for registering said cartridge in a cartridgeposition on said carriage.
 5. The apparatus of claim 3 furthercomprising a drive apparatus for applying a rotational drive to saidsheet cleaning roller, said drive apparatus including a drive couplerfor selectively connecting said cleaning roller to said drive apparatuswhen said cartridge is in said operating position, and for disconnectingsaid cleaning roller from said drive apparatus when said cartridge is insaid maintenance position.
 6. The apparatus of claim 5 wherein saiddrive apparatus includes an electric motor for providing a source ofrotational energy, and said coupler includes mating quickconnect/disconnect elements which are connected when the carriage is inthe operating position, and which are disconnected when the carriage isin the maintenance position.
 7. A sheet cleaning apparatus for cleaningforeign particles from first and second opposed surfaces of a sheet,comprising:a frame; a removable sheet cleaning roller cartridge assemblyincluding a first pair of sheet cleaning rollers, said first paircomprising first and second sheet cleaning rollers rotatably mounted forrotation about first and second sheet cleaning roller axes, each rollercomprising a layer of resilient material defining a peripheral rollersurface with a high surface tack adapted to transfer foreign particlesfrom said sheet to said peripheral roller surface upon contact andsubsequent separation therebetween while affording clean separationbetween the sheet and said peripheral surface, said first and secondrollers disposed adjacent each other with said axes disposed in parallelto receive therebetween a sheet having said surfaces to be cleaned;first and second roller cleaning members respectively disposed adjacentsaid first and second sheet cleaning rollers, each sheet cleaning memberhaving a contact surface with a greater surface tack with respect tosaid foreign particles than said sheet cleaning roller surface, saidcontact surface adapted to transfer said foreign particles from saidperipheral surface of said cleaning rollers to said contact surface ofsaid roller cleaning member, said roller cleaning member having anexternal surface defining said contact surface and a cleaning elementaxis arranged substantially parallel to said respective roller axes;mounting apparatus for mounting said roller cartridge assembly inrelation to said frame, said mounting apparatus permitting ready removaland replacement of said roller cartridge assembly with another rollercartridge assembly to minimize down time of said sheet cleaningapparatus while permitting off-line servicing of said removed rollercartridge assembly.
 8. The apparatus of claim 7 wherein said mountingapparatus is adapted to permit movement of said roller cartridgeassembly between an operating position in an apparatus operating modewherein each sheet cleaning roller is in position for sheet cleaningoperation and a maintenance position during an apparatus maintenancemode wherein said cartridge assembly is accessible for servicing.
 9. Theapparatus of claim 8 wherein said mounting apparatus includes acartridge carriage and a slide apparatus to which said carriage ismounted, said slide apparatus adapted to permit sliding movement of saidcartridge carriage along a slide axis parallel to said roller axes. 10.The apparatus of claim 9 wherein said carriage includes cartridgeposition registration elements for registering said cartridge in acartridge position on said carriage.
 11. The apparatus of claim 9further comprising a drive apparatus for applying a rotational drive tosaid first sheet cleaning rollers, said drive apparatus including adrive coupler for selectively connecting said first sheet cleaningrollers to said drive apparatus when said cartridge is in said operatingposition, and for disconnecting said first sheet cleaning rollers fromsaid drive apparatus when said cartridge is in said maintenanceposition.
 12. The apparatus of claim 11 wherein said drive apparatusincludes an electric motor for providing a source of rotational energy,and said coupler includes mating quick connect/disconnect elements whichare connected when the carriage is in the operating position, and whichare disconnected when the carriage is in the maintenance position. 13.The apparatus of claim 7, wherein said cartridge assembly furtherincludes a second pair of sheet cleaning rollers, said second paircomprising third and fourth sheet cleaning rollers rotatably mounted forrotation about third and fourth sheet cleaning roller axes, each rollerof said second pair comprising a layer of resilient material defining aperipheral roller surface with a high surface tack adapted to transferforeign particles from said sheet to said peripheral roller surface uponcontact and subsequent separation therebetween, said third and fourthrollers disposed adjacent each other with said axes disposed in parallelto receive therebetween a sheet having said surfaces to be cleaned, saidfirst pair disposed adjacent said second pair.
 14. The apparatus ofclaim 7, wherein said cartridge assembly further comprises biasingapparatus for biasing the first and second sheet cleaning rollers apartin the absence of a loading force to facilitate cleaning a relativelythick sheet.
 15. The apparatus of claim 14 wherein said biasingapparatus includes a pair of spring members arranged at respective endsof roller support end rails.
 16. A sheet cleaning apparatus for cleaningforeign particles from at least one surface of a sheet, comprising:aframe; first and second removable sheet cleaning roller cartridgeassemblies, each said assembly including at least one sheet cleaningroller rotatably secured thereto for rotation about a sheet cleaningroller axis, said roller comprising a layer of resilient materialdefining a peripheral roller surface with a high surface tack adapted totransfer foreign particles from said sheet to said peripheral rollersurface upon contact and subsequent separation therebetween whileaffording clean separation between the sheet and said peripheralsurface; a roller cleaning member associated with one of said rollercartridge assemblies having a contact surface with a greater surfacetack with respect to said foreign particles than said sheet cleaningroller surface, said contact surface adapted to transfer said foreignparticles from said peripheral surface of said cleaning roller to saidcontact surface of said roller cleaning member during sheet cleaningoperations, said roller cleaning member having an external surfacedefining said contact surface and a cleaning element axis arrangedsubstantially parallel to said roller axis; mounting apparatus formounting said first roller cartridge assembly in relation to said frame,said mounting apparatus permitting ready removal and replacement of saidroller cartridge assembly with said second roller cartridge assembly tominimize down time of said sheet cleaning apparatus while permittingoff-line servicing of said removed first roller cartridge assembly.